我一直在使用CentOS7的.net core镜像，最近忽然发现8已经出来了，就想升级下环境，毕竟有很多人已经反应7下面有些bug，那升级系统就能解决的事，应该不是啥事吧——因为系统又不是我写的，啊哈哈，bug遇到了也找不到我。
自己写Dockerfile吧
Dockerfile的格式非常简单，几乎没啥学习成本，并且构建起来特别轻松，那么我们就从这个文件写起吧。
# 升级到8，简单，直接抄袭centos7的镜像文件
FROM centos:8
# 构建自己的环境变量，常规的环境变量先加上，避免用的时候为空
# 例如 DOTNET_RUNNING_IN_CONTAINER，就可以用来检测程序是否运行在容器内
ENV DOTNET_CORE_VERSION=3.1 \
DOTNET_FRAMEWORK=netcoreapp3.1 \
# Microsoft's images set this to enable detecting when an app is running in a container.
DOTNET_RUNNING_IN_CONTAINER=true \
TZ=Asia/Shanghai
# 时间区域添加上海的
# CentOS 8 添加中文字体编码,设置本地编码为中文utf-8
RUN yum install -y langpacks-zh_CN
RUN export LANG=zh_CN.UTF-8
RUN echo -e "export LANG=zh_CN.UTF-8" > /etc/locale.conf
RUN echo -e "export LANG=zh_CN.UTF-8" > /etc/profile
RUN source /etc/profile
ENV LANG zh_CN.UTF-8
ENV LC_ALL zh_CN.UTF-8
# 抄袭官网的安装
# Install .NET Core
RUN dotnet_version=3.1.10 \
&& curl -SL --output dotnet.tar.gz https://dotnetcli.azureedge.net/dotnet/Runtime/$dotnet_version/dotnet-runtime-$dotnet_version-linux-x64.tar.gz \
# https://dotnetcli.blob.core.windows.net/dotnet/Runtime/3.1.10/dotnet-runtime-3.1.10-linux-x64.tar.gz
# download slow in china ========
&& dotnet_sha512='7ff09caf2cdff0ae1c75d0ac731267ffa624025137b079134eb9fda15e1ca386af8422ddd3e93ba084853006e7d58bc04bdf232ad3762580e94658ce3dc8f984' \
&& echo "$dotnet_sha512 dotnet.tar.gz" | sha512sum -c - \
&& mkdir -p /usr/share/dotnet \
&& tar -ozxf dotnet.tar.gz -C /usr/share/dotnet \
&& rm dotnet.tar.gz \
&& ln -s /usr/share/dotnet/dotnet /usr/bin/dotnet
# 安装gdiplus 库
# install libgdiplus
# install icu 库，否则提示Couldn't find a valid ICU package installed on the system.
# Set the configuration flag System.Globalization.Invariant to true if you want to run with no globalization support.
RUN yum install -y epel-release && \
yum install -y libgdiplus-devel && \
yum install -y icu && \
yum clean all -y && \
rm -rf /var/cache/yum/*
# 加上中国时区
# chinese timezone
RUN ln -fs /usr/share/zoneinfo/${TZ} /etc/localtime \
&& echo ${TZ} > /etc/timezone
下载慢
微软官方的下载路径太慢了，2个地址都慢。我自己下载好后，修改为本地构建
# 从本地拷贝dotnet 到容器
COPY dotnet-runtime-3.1.10-linux-x64.tar.gz dotnet.tar.gz
# Install .NET Core
RUN dotnet_version=3.1.10 \
# 我们不下载了，太慢，太慢~~~~
# && curl -SL --output dotnet.tar.gz https://dotnetcli.azureedge.net/dotnet/Runtime/$dotnet_version/dotnet-runtime-$dotnet_version-linux-x64.tar.gz \
# https://dotnetcli.blob.core.windows.net/dotnet/Runtime/3.1.10/dotnet-runtime-3.1.10-linux-x64.tar.gz
# download slow in china ========
构建
docker build -t centos8-dotnet31 .
Sending build context to Docker daemon 30.43 MB
Step 1/13 : FROM centos:8
---> 0d120b6ccaa8
Step 2/13 : ENV DOTNET_CORE_VERSION 3.1 DOTNET_FRAMEWORK netcoreapp3.1 DOTNET_RUNNING_IN_CONTAINER true DOTNET_SSL_CERT_DIR /opt/app-root/ssl_dir TZ Asia/Shanghai
---> Using cache
---> 84828b8e519d
Step 3/13 : RUN yum install -y langpacks-zh_CN
---> Using cache
---> 903049fcd58c
Step 4/13 : RUN export LANG=zh_CN.UTF-8
---> Running in 5a59ed12a87c
---> d64659f24088
Removing intermediate container 5a59ed12a87c
Step 5/13 : RUN echo -e "export LANG=zh_CN.UTF-8" > /etc/locale.conf
---> Running in fe1ec4111a72
---> a1ba5fea2b3b
Removing intermediate container fe1ec4111a72
Step 6/13 : RUN echo -e "export LANG=zh_CN.UTF-8" > /etc/profile
---> Running in 68aecf25b603
---> 108ddac88adf
Removing intermediate container 68aecf25b603
Step 7/13 : RUN source /etc/profile
---> Running in 97f728044a65
---> 1ab5ceaf7b82
Removing intermediate container 97f728044a65
Step 8/13 : ENV LANG zh_CN.UTF-8
---> Running in d28d25a03d5b
---> d8ed5480d450
Removing intermediate container d28d25a03d5b
Step 9/13 : ENV LC_ALL zh_CN.UTF-8
---> Running in dd17f73990f9
---> 9dd65bcfaf72
Removing intermediate container dd17f73990f9
Step 10/13 : COPY dotnet-runtime-3.1.10-linux-x64.tar.gz dotnet.tar.gz
---> e74ea72beaa6
Removing intermediate container 8ecb98769565
Step 11/13 : RUN dotnet_version=3.1.10 && dotnet_sha512='7ff09caf2cdff0ae1c75d0ac731267ffa624025137b079134eb9fda15e1ca386af8422ddd3e93ba084853006e7d58bc04bdf232ad3762580e94658ce3dc8f984' && echo "$dotnet_sha512 dotnet.tar.gz" | sha512sum -c - && mkdir -p /usr/share/dotnet && tar -ozxf dotnet.tar.gz -C /usr/share/dotnet && rm dotnet.tar.gz && ln -s /usr/share/dotnet/dotnet /usr/bin/dotnet
---> Running in 7e2bcc123cf4
dotnet.tar.gz: OK
---> 66dd2f8d5681
Removing intermediate container 7e2bcc123cf4
Step 12/13 : RUN yum install -y epel-release && yum install -y libgdiplus-devel && yum clean all -y && rm -rf /var/cache/yum/*
---> Running in ef8d63b1208c
Last metadata expiration check: 2:49:48 ago on 2020年11月13日 星期五 19时58分37秒.
Dependencies resolved.
================================================================================
Package Architecture Version Repository Size
================================================================================
Installing:
epel-release noarch 8-8.el8 extras 23 k
Transaction Summary
================================================================================
Install 1 Package
Total download size: 23 k
Installed size: 32 k
Downloading Packages:
epel-release-8-8.el8.noarch.rpm 39 kB/s | 23 kB 00:00
--------------------------------------------------------------------------------
Total 10 kB/s | 23 kB 00:02
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : epel-release-8-8.el8.noarch 1/1
Running scriptlet: epel-release-8-8.el8.noarch 1/1
Verifying : epel-release-8-8.el8.noarch 1/1
Installed:
epel-release-8-8.el8.noarch
Complete!
Extra Packages for Enterprise Linux Modular 8 - 9.9 kB/s | 97 kB 00:09
39 files removed
---> dfe64e392df6
Removing intermediate container 1efb1e7b5ee2
Step 13/13 : RUN ln -fs /usr/share/zoneinfo/${TZ} /etc/localtime && echo ${TZ} > /etc/timezone
---> Running in ffc50b140330
---> c263956a0d45
Removing intermediate container ffc50b140330
Successfully built c263956a0d45
检查容器
打包下来 大小： 405 MB。自我感觉良好，因为我没有看见别人构建的Dockerfile，这个足够精简，哈哈~~ 进入容器查看dotnet信息
dotnet --info
It was not possible to find any installed .NET Core SDKs
Did you mean to run .NET Core SDK commands? Install a .NET Core SDK from:
https://aka.ms/dotnet-download
Host (useful for support):
Version: 3.1.10
Commit: 1721e39439
.NET Core SDKs installed:
No SDKs were found.
.NET Core runtimes installed:
Microsoft.NETCore.App 3.1.10 [/usr/share/dotnet/shared/Microsoft.NETCore.App]
To install additional .NET Core runtimes or SDKs:
https://aka.ms/dotnet-download
